We often take a plentiful supply of clean drinking water for granted. In the future we will depend more on groundwater supplies and they must be protected from contamination. Contaminated groundwater can endanger people’s health and the environment.

On this page: Communities and groundwater, Groundwater contaminants, Prevention is better than cure, What Waikato Regional Council is doing, Supply owners, You can help!, More Information.

Communities and groundwater

Many Waikato rural communities rely on groundwater for their water supply. Community groundwater supplies in the Waikato include:

• about 90 schools
• about 30 community supplies managed by district councils
• numerous motor camp supplies.

Groundwater contaminants

Contamination of groundwater usually happens gradually and can go unnoticed for some time. Most contaminants come from the ground surface, so shallow water table aquifers with thin soil cover are easily contaminated.

Contamination of groundwater can come from:

• human and animal effluent
• disposal of industrial wastewater
• leakage from landfills
• fertilisers and pesticides
• leakage from pipelines and underground storage tanks
• seepage from mining operations
• salt water intrusion.

Find out more about monitoring groundwater.

Prevention is better than cure

It is much easier to prevent groundwater contamination than to try to fix it afterwards. Trying to clean up contaminated drinking water is very costly and often not practical.

By comparison, protecting source water costs very little and is a ‘common sense’ approach to safeguarding public health and the environment.

Community groundwater supplies must be registered with the Ministry of Health and monitored to see if they meet drinking water standards. The drinking water standards for New Zealand list maximum acceptable values for:

• microbial contaminants
• chemical contaminants
• ‘aesthetic’ values (relating to nuisance rather than health concerns, for example, staining).

What Waikato Regional Council is doing

Waikato Regional Council uses a range of methods to manage groundwater resources, including:

• Regulating activities likely to cause contamination, such as wastewater discharge.
• Making sure wells are properly constructed, completed and separated from likely sources of contamination.
• Educating the public (in partnership with health authorities and district councils) about ground water source protection and the need for appropriate land use near groundwater supplies.
• Working with industry to develop codes of practice and industry guidelines.
• Monitoring ground water quality, investigating issues and providing information to the public.

Supply owners

Supply owners or managers should develop risk management plans to protect groundwater drinking sources. These include:

• An assessment of how vulnerable the source water is to contamination.
• Prevention and restoration measures.
• Information for supply users on the risk of contamination.
• Ongoing monitoring and review.

You can help!

Communities can protect groundwater supplies by:

• Making sure wells are properly completed, sealed (including a concrete pad), and protected to prevent surface contamination.
• Storing chemicals away from wells.
• Registering supplies and monitoring water quality.
• Defining well-head protection areas.
• Documenting potential sources of contamination.
• Working with councils and advocating for appropriate land use restrictions.
• Developing and regularly reviewing risk management plans.

Well-head protection areas control certain land uses in the area contributing water (and potentially contaminants) to a groundwater supply. There are a number of methods which can be used to map well-head protection areas and we advise consulting a specialist hydrogeologist.

More Information

 

Learn more in our indicators that measure groundwater quality in the Waikato region, including nitrate and pesticide levels.

Check out the national drinking water standards on the Ministry of Health website (online publications).